Lubricant



Patented May 21, 1940 UNITED STATES PATENT OFFICE No Drawing.

Application August 25, 1937,

Serial No. 160,824

21 Claims.

This invention relates to improvements in solid lubricants and moreparticularly to that class of lubricants designed to be used forlubricating and sealing the moving surfaces of valves.

One object of the invention is to maintain the consistency of suchlubricants substantially stable over wide temperature ranges.

Another object of the invention is to render the lubricants insoluble inpetroleum hydrocarbons and aqueous liquids and unaffected by steam.

Another object of the invention is to insure suflicient stability atelevated temperatures to retain the lubricating and sealing propertiesof the lubricants substantially intact.

It has been found that the water insoluble metal soaps of thickenedfixed oils have the properties desirable for the services in which theselubricants are used. The water insoluble metal soaps may be made" bysaponifying the oils with sodium hydroxide to form sodium soaps. Thewater solution of the sodium soap is added to a water solution of metalsalt. The insoluble metal soaps thus formed are washed free of any saltsand dried. The soaps are then blended or compounded by heating andstirring with a liquid that is insoluble in water and petroleumhydrocarbons to form the lubricant having the desired qualities.

The water insoluble metal soaps which have been found suitable are thoseof thickened vegetable or animal oils. Such oils include castor, rapeseed, ,flsh, linseed, corn, cotton seed, tung and soja bean. Thisthickening process may consist of blowing, polymerizing, vulcanizing oroxidizing. In the case of blowing, which comprises blowing air throughthe oils at elevated temperatures, the oils are caused to take up oxygenand form -OH groups and two or more of the molecules of the oil arecaused to combine to form larger molecules. The vulcanized oils areformed by heating in contact with sulphur whereby the molecules of oilcombine to form larger molecules. Consequently, it will be apparent thatall highly blown, vulcanized, oxidized or polymerized animal orvegetable oils can be made into metal soaps that are insoluble in bothwater and petroleum hydrocarbons.

Typical metal salts to which the sodium soap may be added to form waterinsoluble metal soaps are aluminum, magnesium or calcium sulphates.

The material with which the water insoluble metal soaps may be blendedto form lubricants having the desired properties may be chosen fromthose polar non-polar substances or liquids of high molecular weight.Such materials include the compounds belonging to the glyptal resinclass, such as rezyl balsam and have the properties of being liquid at40 F. and having a solubility oi less than 2% in gasoline at 70 F.; orthe thickened fixed oils, such as castor oils, blown rape seed oil, andblown fish oil; or the mono-esters oi. the acids of thickened fixed oilsincluding the mono-esters of blown castor oil acid, blown rape seed oilacid, blown fish oil acid and polyhydric alcohols such as glycerine orethylene glycol. The preferred rezyl balsam is that known to thoseskilled in the'art as No. 33. This material is an ester made fromglycerol and phthalic acid and is known as a compound belonging to theglyptal resin class. In preparing this material a resin is formed byheating glycerol and phthalic acid and forming a composition in whichthere are still some free -OH groups left. A nonoxidizing fatty'acidsuch as stearic acid is added which reacts with a part of the remaining--OH groups, tending to make the resin more water resistant and alsocontributing to molecular weight, but not increasing resin formation.This class of materials generally has -OH groups that tend to make theminsoluble in hydrocarbons and a number of hydrocarbon groups that tendto make them insoluble in water. If the number of -OH groups andhydrocarbon groups is properly balanced it is possible to make resinsthat are only slightly soluble in water and hydrocarbons. Such acompound is rezyl balsam" No. 33, and as this particular material haslarge molecules it has a low vapor pressure at high temperatures andtends to be less soluble in all solvents.

In carrying out this invention, a. preferred formula is as follows:

' Percent Thickened fixed oil 26.0 Sodium hydroxide 3.2 Metal salt 9.8Water 26.0 Rezyl balsam 35.0

In making this improved lubricant the thickened fixed oil, such as airblown castor oil, is saponified with the sodium hydroxide in water. Tothe sodium soap thus formed there is added a solution made from themetal salt and water, such as aluminum sulphate and water. The insolublesoap which results from the mixture is first washed free of all salts ona filter, and,

after being placed in a suitable vessel, the stabilizing agent such asrezyl balsam is added thereto. The mixture is then heated toapproximately 400 F. with constant stirring until all the water isevaporated and the aluminum soap is completely suspended.

It will be understood that other polar non-polar material, such as thethickened fixed oils, including those mentioned, may be substituted forthe compound of the glyptalresin class given in the foregoing formula.Also the mono-esters of the acids of thickened fixed oils and glycerineor ethylene glycol.

The resulting product after cooling, comprises a heavy, viscous materialwhich is insoluble in water and petroleum hydrocarbons, such asgasoline, kerosene, mineral oil and the like, and has sufiicientconsistency at 400 F. to seal and lubricate the seating surfaces ofvalves subjected to high pressures. If desired, a small percentage of athickened fixed oil, such as blown castor oil, may be added to stabilizethe suspension at lower temperatures. In addition, to make the lubricantmore solid, a small percentage of a vegetable wax, such as carnauba wax,may be added. As it is usual to form the lubricant into stick form forconvenience in use on lubricated valves, the wax imparts certain plasticproperties which enables these sticks to retain the desired shape.

An average composition of the lubricant is as follows:

Percent Water insoluble metal soap of thickened fixed oil 38.2 Rezylbalsam A 51.8 'I'hickened fixed oil 2.8 Vegetable wax 7.2

As stated, the thickened fixed oil and vegetable wax, can be omitted ifthe properties they impart are not desired. The ratio of waterinsolublemetal soap to rezyl balsam can vary between limits of 25% waterinsoluble metal soap and 75% rezyl balsam to water insoluble metal soapand 45% rezyl balsam. Taking these variations into account and includingthe thickened fixed oil and vegetable wax the composition limits maycomprise:

Percent Water insoluble metal soap of thickened fixed oil 22.2 to 49.0Rezyl balsam 40.0 to 66.8 Thickened fixed oil 2.8 Vegetable wax 7.2

It will be understood that while the invention 1 is ideally suited foruse in lubricating and sealing the'moving surfaces of valves it is notlimited to such applications, but finds a Wide field of usefulness,particularly in devices where solvent action is of importance such aspump and valve packing lubricants.

I claim:

1. The process of manufacturing solid lubricants which comprises mixinga water insoluble metal soap of thickened fixed oil with a polarnon-polar material of high molecular weight having sufiicienthydrocarbon groups to be substantially insoluble in water and sufficienthydroxyl groups to be substantially insoluble in petroleum hydrocarbons,and heating said mixture until the water insoluble metal soap iscompletely suspended.

2. The process of manufacturing solid lubricants which comprises mixinga water insoluble metal soap of thickened fixed oil with-a polarnon-polar material of high molecular weight having sumcient hydrocarbongroups to be substantially insoluble in water and sufiicient hydroxylgroups to be substantially insoluble in petroleum hydrocarbons, heatingsaid mixture until the water insoluble metal soap is completelysuspended, and adding stabilizing and solidifying agents.

3. The process of manufacturing solid lubricants which comprisessaponifying a thickened fixed oil with sodium hydroxide in water,processing with a water solution of a metal salt until a water insolublesalt-free metal soap is formed, adding rezyl balsam, and heating themixture until the water insoluble metal soap is completely suspended.

4. The process of manufacturing solid lubricants which comprisessaponiiying air blown castor oil with sodium hydroxide in water,processing with a water solution of aluminum sulphate until a waterinsoluble salt-free aluminum soap is formed, adding rezyl balsam, andheating the mixture until the aluminum soap is completely suspended.

.5. A solid lubricant comprising a water insoluble metal soap ofthickened fixed oil and a polar non-polar material of high molecularweight having sufiicient hydrocarbon groups to be substantiallyinsoluble in water and sufficient hydroxyl groups to be substantiallyinsoluble in petroleum hydrocarbons.

6. A solid lubricant comprising a water insoluble metal soap ofthickened fixed oil and a compound of the glyptal resin class which isliquid above 40 Fahrenheit and has a solubility of less than two percent in gasoline at 70 Fahrenheit.

7. A solid lubricant comprising a water insoluble metal soap ofthickened fixed oil, a compound of the glyptal resin class which isliquid above 40 Fahrenheit and has a solubility of less than two percent in gasoline at 70 Fahrenheit, and a small percentage each ofstabilizing and solidifying agents.

8. A solid lubricant comprising about 25% to 55% of a water insolublemetal soap of thickened fixed oil and 75% to 45% of a polar non-polarmaterial of high molecular weight having suflicient hydrocarbon groupsto be substantially insoluble in water and sufiicient hydroxyl groups tobe substantially insoluble in petroleum hydrocarbons.

9. A solid lubricant comprising about 25% to 55% of a water insolublemetal soap of thickened fixed oil and 75% to 45% of a compound of theglyptal resin class which is liquid above 40 Fahrenheit and has asolubility of less than two per cent in gasoline at 70 Fahrenheit.

10. A solid lubricant comprising about 25% to 55% of a water insolublemetal soap of thickened fixed oil and 75% to 45% of thickened fixed oil.

11. A solid lubricant comprising about 25% to 55% of a water insolublemetal soap of thickened fixed oil and 75% to 45% of the mono-ester ofthe acid of thickened fixed oil and a polyhydric alcohol.

12. A solid lubricant comprising about the following formula:

Percent Water insoluble metal soap of thickened fixed oil 22.2 to 49.0 Acompound of the glyptal resin class (liquid above 40 Fahrenheit and lessthan two per cent soluble in gasoline at 70 Fahrenheit) 40.0 to 66.8

solidifying agents.

13. A solid lubricant comprising about the following formula:

Percent Water insoluble metal soap of fixed oil 22.2 to 49.0 A compoundof the glyptal resin class (liquid above 40 Fahrenheit and less than twoper cent soluble in gasoline at Fahrenheit) 40.0 to 66.8 Thickened fixedoil 2.8 Vegetable wax 7.2

' 14. A solid lubricant comprising about the following formula:

Percent Water insoluble metal soap of fixed oil 22.2 to 49.0 Rezylbalsam 40.0 to 66.8 Thickened fixed oil 2.8 Vegetable wax 7 .2

16. A solid lubricant comprising about the following formula:

Percent Aluminum soap of blown castor oil 22.2 to 49.0 Rezyl balsam 40.0to 66.8 Blown castor oil 2.8 7.2

Carnauba wax 17. A solid lubricant comprising about the followingformula:

Percent Aluminum soap of blown castor oil 38.2 Rezyl balsam 51.8 Blowncastor oil 2.8 Carnauba wax 7.2

18. A solid lubricant comprising a water insoluble metal soap ofthickened fixed oil and a polar non-polar material of high molecularweight having sufflcient hydrocarbon groups to be substantiallyinsoluble in water and suflicient hydroxyl groups to be substantiallyinsoluble in petroleum hydrocarbons, said material being liquid above 40F. and having a solubility of less than 2% in gasoline at 70 F.

19. A solid lubricant comprising a water insoluble metal soap ofthickened fixed oil and a polar non-polar material of high molecularweight having sufilcient hydrocarbon groups to be substantiallyinsoluble in water and sufilcient hydroxyl groups to be substantiallyinsoluble in petroleum hydrocarbons, said lubricant having sufiicientconsistency at 400 F. to seal and lubricate the seating surfaces ofvalves subjected to high pressures.

20. A solid lubricant comprising a water insoluble metal soap ofthickened fixed oil and a polar non-polar material of high molecularweight having suflicient hydrocarbon groups to be substantiallyinsoluble in water and sufiiclent hydroxyl groups to be substantiallyinsoluble in petroleum hydrocarbons, said material being liquid above 40F. and having a solubility of less than 2%, in gasoline at 70 F., saidlubricant having sufficient consistency at 400 F. to seal and lubricatethe seating surfaces of valves subjected to high pressures.

21. A solid lubricant comprising a water insoluble metal soap ofthickened fixed oil and rezyl balsam".

HER-MAN E. BAILARD.

